/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.runners.core.construction.graph;



import com.google.auto.value.AutoValue;

import com.bff.gaia.unified.model.pipeline.v1.RunnerApi;

import com.bff.gaia.unified.model.pipeline.v1.RunnerApi.ExecutableStagePayload.UserStateId;

import com.bff.gaia.unified.model.pipeline.v1.RunnerApi.PTransform;

import com.bff.gaia.unified.runners.core.construction.ParDoTranslation;



import java.io.IOException;



/**

 * A reference to user state. This includes the PTransform that references the user state as well as

 * the local name. Both are necessary in order to fully resolve user state.

 */

@AutoValue

public abstract class UserStateReference {



  /** Create a user state reference. */

  public static UserStateReference of(

	  PipelineNode.PTransformNode transform, String localName, PipelineNode.PCollectionNode collection) {

    return new AutoValue_UserStateReference(transform, localName, collection);

  }



  /** Create a user state reference from a UserStateId proto and components. */

  public static UserStateReference fromUserStateId(

      UserStateId userStateId, RunnerApi.Components components) {

    PTransform transform = components.getTransformsOrThrow(userStateId.getTransformId());

    String mainInputCollectionId;

    try {

      mainInputCollectionId =

          transform.getInputsOrThrow(ParDoTranslation.getMainInputName(transform));

    } catch (IOException e) {

      throw new RuntimeException(e);

    }

    return UserStateReference.of(

        PipelineNode.pTransform(userStateId.getTransformId(), transform),

        userStateId.getLocalName(),

        PipelineNode.pCollection(

            mainInputCollectionId, components.getPcollectionsOrThrow(mainInputCollectionId)));

  }



  /** The id of the PTransform that uses this user state. */

  public abstract PipelineNode.PTransformNode transform();

  /** The local name the referencing PTransform uses to refer to this user state. */

  public abstract String localName();

  /** The PCollection that represents the input to the PTransform. */

  public abstract PipelineNode.PCollectionNode collection();

}